Equine Ulcers and Stress: Danish Study Looks at Link

It is not unusual for horses to get stomach ulcers. But how important are the ulcers? Is it because the horse is stressed that it gets stomach ulcers? And does a horse with stomach ulcers have a greater tendency to crib or have other types of abnormal behavior?

Scientists from the Faculty of Agricultural Sciences at Aarhus University in Denmark are investigating the possible connection between stomach ulcers and stress in horses.

"Even though there are a lot of indications that ulcers are common in horses, we don't know how important they are for the horses' level of stress and reactivity despite the fact that it could impact on their welfare and their daily use," said Senior Scientist Jens Malmkvist, PhD, leader of the newly started project..

Some studies from abroad have found surprisingly high frequencies of damage to the stomach lining of horses up to 93% in horses that were studied when they were in training. In Denmark the latest figures show that over half of the horses have ulcers to a smaller or larger degree.

Stressed or not stressed?

In the latest project the scientists will study three aspects of stomach ulcers in horses: Are horses with ulcers more stressed? Are they more sensitive to stress? And do horses with ulcers have a greater tendency to crib or perform other types of abnormal behavior?

Approximately 100 horses will be investigated in order to find out if they have ulcers and, if that is the case, how serious the ulcers are. From this group of horses the scientists will establish two smaller study groups. The control group will consist of 30 horses with no or little damage to the stomach lining, while 30 horses with serious damages to the stomach lining will comprise the stomach ulcer group.

The horses' behavior and level of stress will be measured in different situations. The scientists will systematically register the horses' reactions and behavior in feeding situations, in the horses' daily lives at home in their own stalls, and in situations that elicit fear in the horses.

The work is supported by the Horse Levy Fund and is being carried out in collaboration with Danish horse veterinarians and the University of Veterinary Medicine in Vienna.

"The project will contribute to our understanding of what importance stomach ulcers has for horses, which can also impact the daily use and handling of horses," Malmkvist said.